PYTHON-5414 Fix "module service_identity has no attribute SICertificateError" when using pyopenssl

[mpsijm]

When there is a mistake in the certificates configuration, PyMongo would give the following error:

pymongo.errors.ServerSelectionTimeoutError: module service_identity has no attribute SICertificateError, Timeout: 30s, Topology Description: <…>

Because the except block expected non-existing errors, the error gets transformed to "module … has no attribute …". The errors in the service_identity have never had the SI prefix:
https://github.com/pyca/service-identity/blob/18.1.0/src/service_identity/exceptions.py
It looks like the errors were imported with an alias before, but this aliasing was (only partially) removed when rewriting to lazy imports in this commit:
42a08c4#diff-b277a2f4cfbb5decab333d0b90a08a4ad64b91fb1691ed8412b15949d1aaceee
The lazy imports were removed again in this commit, but the error remained:
49987e6#diff-b277a2f4cfbb5decab333d0b90a08a4ad64b91fb1691ed8412b15949d1aaceee
After changing the expected errors manually in my virtual environment, the error I received earlier turned into this, so I could continue debugging my certificates configuration:

pymongo.errors.ServerSelectionTimeoutError: […]: ("VerificationError(errors=[IPAddressMismatch(…)])",) (configured timeouts: socketTimeoutMS: 20000.0ms, connectTimeoutMS: 20000.0ms), Timeout: 30s, Topology Description: <…>

Most likely, the # type: ignore[misc] comment can now also be removed (but I have not set up this repository for development on my machine, so I'll let the automated checks be the judge of that).

[ShaneHarvey]

Thanks for the detailed report and fix! It looks good to me but I'm going to see if I can add a regression test before merging.

[mpsijm]

Sounds good, thanks! If it helps coming up with the test: in the end, I had two mistakes in my configuration, I forgot which one triggered this code path (maybe it was both):

• I was connecting to 127.0.0.1, rather than the domain name for which the Mongo server had a TLS certificate.
• I forgot to set the authMechanism option to MONGODB-X509 (I did have tls, tlsCertificateKeyFile, and tlsCAFile set correctly).

[mpsijm]

I see that the regression test will be added in #2385 🙂 Thanks for merging! 😄 ❤️